| 학회 |
한국고분자학회 |
| 학술대회 |
2007년 봄 (04/12 ~ 04/13, 제주 ICC) |
| 권호 |
32권 1호 |
| 발표분야 |
고분자 구조 및 물성 |
| 제목 |
Solid-State Characterization of Polyethylene Reactor Powders and Their Structural Changes upon Annealing |
| 초록 |
Polyethylene reactor powders prepared under different conditions were characterized using transmission electron microscopy, solid-state nuclear magnetic resonance and X-ray diffraction techniques. A unique domain morphology, quite different from the usual melt- or solution- crystallized lamellar structure, was observed, independent of polymerization temperature (Tpoly). Annealing of reactor powders caused the aggregation of these crystalline domains, due to the signicant molecular motion of the amorphous chains, before melting. The critical temperature was 20oC higher than each Tpoly, and corresponded to the temperature at the active catalyst site producing the chain growth. The morphologies of powders prepared at the lower Tpoly contained smaller crystals that exhibited a constrained monoclinic form. In contrast, only usual orthorhombic crystals of larger size found within the powder prepared at the higher Tpoly. These results suggest that the competitive processes of chain propagation and crystal growth upon polymerization may lead to unique variations of the crystalline and amorphous phases, but with similar intermediate components in the phase that connects them. |
| 저자 |
Hiroki UEHARA1, Ayako UEHARA2, Masaki KAKIAGE1, Hiroshi TAKAHASHI2, Syozo MURAKAMI1, Takeshi YAMANOBE2, Tadashi KOMOTO1
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| 소속 |
1Department of Chemistry, 2Gunma Univ. |
| 키워드 |
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| E-Mail |
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